1. Field of the Invention
This invention relates in general to display devices and in particular to an easel for displaying sheets of paper.
2. Description of the Prior Art
An easel or other display device generally uses a fixed backing plate to display paper or similar sheet material. The prior art in this field encompasses devices employing various methods of holding the material in a desired position. A simple method is to position the backing plate at such an angle that the force of gravity prevents the outermost page or sheet from turning, as disclosed in U.S. Pat. Nos. 959,479 and 2,549,306. A related arrangement is disclosed in U.S. Pat. No. 2,877,581, in which the used pages are turned up and held out of sight by the weight of a stiff front cover panel which extends down over the pages. Similarly, U.S. Pat. No. 1,574,245 discloses a calender where the pages of the expired months are supported out of sight not only by the front cover panel, but by a perforation in the page corresponding to a mounting nail which maintains it.
Several types of fastening means other than cover panels are known. For example, U.S. Pat. No. 869,411 discloses the use of a sheet-retaining tongue and U.S. Pat. No. 2,550,386 discloses the use of a slidably mounted plunger. U.S. Pat. No. 1,061,133 discloses a calendar employing a U-shaped clamp to hold up the pages while the music leaf turner disclosed in U.S. Pat. No. 614,372 utilizes several finger-like clamps. U.S. Pat. No. 286,736 discloses a hanging chart wherein the pages are supported by pins which extend through perforated eyes in the page.